Electric furnace.



I. W. BROWN.

ELECTRIC FURNACE. APPLICATION map AUG. 12. 1912.

Patented J u ly 11, 1916.

4 SHEETSSHEET l.

INVENTOR JOHN w. BROWN BY Q3461? a HAM .WITNESSES d Arr-5 R N av.

J. W. BROWN.

ELECTRIC FURNACE.

' APPLICATION FILED AUG. 12. 1912. 1,1 90,856. Patented July 11, 1916.

4 SHEETS-SHEET 2.

' WITNESSES 7 INVENTOR ATTORNEY J. W. BROWN.

ELECTRIC FURNACE.

APPLICATION FILE'D AUG. 12, 1912.

Patented July 11, 1916.

SHEETS-SHEET 3.

87 E 9 5222555 INVENTOR W 49 JOHN w. BROWN 16;; ATTORNEY- for heatingarticles, particularly :roinv w. BROWN, or CLEVELAND, osro,

LAKEWOOD, OHIO, ASSIGNQR TO NATIONAL CARBON G0... @31

A CORPORATION E NEIV JERSEY.

ntncrnrc chanson.

Specification of Letters Eatent.

Patented ply 111, third.

Application filed August 12, 1912. Serial No. 714,516.

To all whom it may concern Be it known that I, JOHN W. BROWN, a.resident of Lakewood, in the county of Cuyahoga, in the State of Ohio,have invented new and useful Improvements in Electric Furnaces, ofwhichthe following is a clear and exact description.

This invention relates to electric furnaces those made is adaptedoicarbonaceous materials. It

carbon to the ggaphitization of brushes,

plates andaothercarbon articles, although:

it can equally as well be used for heating other articles. V

In my application Serial No. 702118, June 6, 1912, I have disclosed. amethod of heating articles in independent units. Ihis applicati themethod set forth in the, above identified application.

One object of the invention is toarrange series of heating units so thatan operator can moreaeasily carry out the heating process.

Another object slowly fora certain time is to heat the articles beforesending the v full-heating current through them.

' the box.

Other objects will appearin the appended description.

In the drawings: Figure 1 is a view of a heating unit with the articlesin place. Fig. 2 is a transverse section of the box shown in Fig. 1after charcoal has been placedaround the articles. Fig. 3 is a view ofthe device used in placing the articles in Fig. l is a view of thedevice shown in Fig. 3 before the articles are placed therein. Fig. 5 isa top view of the complete furnace arrangement. Fig. 6 is a sectionalelevation taken on the line A-A of Fig. 5. Fig. 7

' electrodes and the means for applying pressure thereto. .Fig. 8- is anend V ew oi the apparatus shown in Fig. 7. Fig. 9 is a sectional view ofthe electrode end and the terminal clamp. Fig. 10 is a sectional Viewtaken on the line 13-43 of Fig. 9. Fig. 11 is a semi-diagrammatic viewof the hydraulic system and the electrical circuits. Fig. 12 isadetailed View of the catch and the stop-therefor. 3

Referring to Fig. 1, each heating unit (1) consists of a boxlikestructure made of as bestos board or any other good heat resistndiscloses means for carrying out.

is a view of parts of the a the device (7) is used.

ing material that is a nonconducter of electricity. The box may bereinforced at the corners by angle irons (2). Each end has an 'OPEIIIHE;(3) to receive the electrodes, which may be of any shape, dependihg upontheshape of the electrodes. Carbon blocks (4, 5) fit loosely in the boxat each end. The articles (6) are clamped in place between the carbonblocks (a, 5) by means of screws (8 and 9) at one end of the box.

In Figs. 3 and a is shown a device (7) for corn eniently placing thearticlesin the box. This consists of two-boards (8 and 9) fastenedtogether to form an angular arrangement. Two slides (10 and 11) aresecured in the ends of the'boards (8 and 9-) so as to slide freely inthe slots (12 and 13). The articles (6) are put in the device as shownin Fig. 3, and then it is placed between the carbon blocks (5) in thebox with the center line of the articles approximately in line with thecenter of the blocks. The screws (8 and 9) are then manipulated to forcethe blocks i and 5) together to compress the articles and hold them inplace. The slides (10 and 11) are pushed in as the blocks compress thearticles and hence the device (7) can be readily removed. With thearticles clamped in position there is a space between them and the sidesand bottom of the box. Granular charcoal is then poured in the spacearound the articles as shown in 'Fig. 2. This is to prevent the undueloss of heat and the combustion of the carbon articles.

The use of the device (7) can be dispensed with if desired and thearticles placed in the box a few at a time. In this case a layer ofcharcoal should first be spread in the bottom of the box and a strip ofcard board (1a) laid on top to present a smooth surface on which thearticles can rest. Ihe

latter may then be placed on the strip of card board and charcoal placedat the sides and on top of the articles. When the articles are carefullyplaced in the box in this manner it is not necessary to apply pressureto them to hold them in place, as when When the device 7) is usedthe-strip of card board is of course omitted.

Referring to Fig. 5 and Fig. 6, a foundation whose walls (15) may bemade of brick, concrete or other material supports against'the end ofthe electrode.

the apparatus for conveying the heating units to the heating means. Afloor (16) which may be made of any material, rests on the walls (15). VPillow blocks (17) fastened to the floor (16)"carry a shaft (18) of aFerris wheel arrangement, which has a plurality ofpairsof arms (19)radiating therefrom, each pair of arms being pivotally jointed to aheating unit (1) by pins (20). The arms (19) on each side may be joinedtogether by braces (21).

At the left of the pillow blocks as shown in Figs. 5 and 0, are arrangedthe electrodes for heating the articles in the units (1). If carbonarticles are heated at a high amperage so as to graphitize them in averyshort time they are liable to warp and crack. This tendency islessened if the articles are heated slowly by a moderate current beforesending a heavy current through them. This may be accomplished byradiating the current with only one pair hf electrodes, but I have showntwo pairs of electrodes. One pair (22, 23) carries a moderate currentand serves to preliminaily heat the article while the other pair (24-25) carries aheavy current of TIOZHBQQ'hO 5000 amperes to graphitizethe articles. The electrodes are adapted to put pressure on the articlesin the boxes '(1) as described in my application herein referred. to.

pressure maybe applied in various ways, but I have shown fluid pressurecylinders (26, 27, 26, 27",) having piston rods (28, 29, 28, 29') joinedto the electrodes (22, as, as, 25;.

The piston rod 28 (Figs. 9 and'lO) has a head (30) that fits in adepression between the plates (31 and 32). Plates 33 and 34 are clampedto the electrode (28) by means of bolts (35). Copper plates (36) are clampedbetween the plates (33, 34) and the electrode. The electricalconductor may be fastened to one plate at the lug (37). The plates (33,34) have cars (37) adapted to receive pins 38 which hold the plate (32)The electrode must therefore move forward and backward with the pistonrod. All the electrodes are connected to the piston rods in this samemanner.

The fluid pressure cylinders are su ported by heavy brackets (39) so asto rigidly connected to the floor (16). The electrodes rest on rollers(40) brackets (41).

The operation will now be described. The operator stands at the righthand side of the Ferris wheel as shown in Fig. 1, and fills the box inposition A as previously described. The catch (42) which is pivoted tothe floor (16) is then swung back against the stop (43) and the Ferriswheel rotated till the filled box reaches position B. The

journaled in,

switch (46) to be closed. The current can be regulated to any amount byany means such as the variable inductance (47) in cir- ,cuit with theauxiliary heating electrodes (22, 23),. The operator then fills anotherbox while the box in position D is being,

heated. The auxiliary heating may be accomplished by using variouscurrent. densities depending upon the character of the article to beheated. The desire is to use a current density that will heat thearticle slowly and prepare it for the final heating which will takeplace in position E. The auxiliary current should preferably be turnedon the same leng'thof time as the main heating current. The reason forthis is that one switch .in the primary of the transformers will then besufiicient to open and close the circuit for both heating circuits.current may be switched on for a time di ferent than that of the maincurrent.

After a certain time the operator opens switch 44 and causes the mainswitch (46) to open. The valve (44) is turned to admit pressure tocylinders 26 and 27 so that the electrodes 22 and 23 are withdrawn. Thewheel is then revolved till the box first filled moves to position E.The valve (44) is then turned back to admit pressure to the cylin dersto force the electrodes 22, 23, 24 and 25 against the articles in thetwo boxes, and the main switch (46) is closed. The articles in the boxat position E have been preliminarily heated and a heavy heating currentis now sent through them. The value of the main heating current may beany value desired. By using a current of 3000 to 5000 amperesper sq.inch, I have graphitized carbon in 20 seconds. For most articles,however, a less current density is preferable, as articles are liable tobecome porous when such high current densities are used. It istherefore, preferable to heat most articles by means of current of lessdensity such that they will be aphitized in about 10 or more minutes. ena sufficient time has elapsed the circuit is broken and the electrodesare withdrawn as before. The next box having been filled by the o eratorthe apparatus is turned so that the ully heated box is in position F.The box in position D is thenpreliminarily heated and the box inposition E is fully heated as before. Finally on the next movement thebox is turned by the trip (48) and the contents dumped on the cover(49). The weight of the articles However, if desired, the auxiliarcauses the cover to rise into its former position. The heated articlesas well as carbon blocks (4 and 5) being covered by charcoal and havinginsufficient air supply in the bin (50) will not burn. Water pipes (52)may be used to cool the articles off so that they may be'taken outthrough the door (53) sooner than they otherwise could.

When the cooled articles are removed through the door the granularcharcoal will fall through the grating (54) and may be-removed by anymeans such as a conveyer (55). The articles may be removed through door(56).

It is not necessary to use two sets of electrodes. QThe same result canbe accomplished with only one set with regulating means in circuit sothat the current at first can be kept at lower values to heat the articles slowly. Then by means of the regulator the current can be increasedto a high value. The electrodes (24: and 25) can therefore beomitted-and the regulator (47) or any other regulating means can be usedto grade the current to accomplish both the preheating and the finalheating. The use of only one set of electrodes, however, will require alonger time to treat the articles, asthe total time is the sum of thetime of the preheating and the time of the final heating.

Having described my invention, what I claim is:

1. In electric furnaces, a plurality of independent furnace unitscontaining charges to be heated, a support for said units, electrodesfor heating the charges and means for causing relative movement betweensaid support and the electrodes to place said electrodes adjacentdifferent units on the support.

2. In electric furnaces, a plurality of furnace units, means wherebycharges contained in said units may be heated and a conveyor for movingthe units into position to be acted upon by said first mentioned means.7

3. In electric furnaces, a plurality of fur-- nace units adapted tocontain charges to be heated, electrodes for heating the charges, aconveyer for moving the units successively between the electrodes andmeans for supporting said units on the conveyer.

4. In electric furnaces, a plurality of furnace units, means wherebycharges contained in said units may be heated, supporting means for theunits, means for moving said supporting means and said heating meansrelative to each other to place the heating means successively adjacentdifferent units on the support.

' 5. In electric furnaces a plurality of furnace units adaptedto containcharges to be heated, a supporting frame for said units,

electrodes for heating the charges, and means for moving said frame toplace the units successively between the electrodes,

6. In electric furnaces, electrodes, a heat ing unit having conductingend walls, means for producing relative movement between the electrodesand the heating unit, and means for moving said electrodes against saidconducting end walls. I

T. In electric furnaces, electrodes, a heating unit having conductingend walls, means for producing relative movement between the electrodesand the heating unit, means for moving the end walls to engage a chargeand means for moving said electrodes against said conducting end walls.

8. in electric furnaces, a plurality of furnace units, electrodes fortrea ing charges contained in said units, a chamber receiving thecharges when heated and means for moving the units to the electrodes tobe heated and away from time to be deposited in said chamber. 7

9. In electric furnaces, a furnace adapted to contain charges to be heheating electrodes spaced apart, means for moving the electrodes towardand from each other, means for moving said unit between the electrodesand controlling means tc cause said first mentioned means to move thedoc I trodes against the charges in said unit to apply pressure thereto.

10. in electric furnaces, a f..rnace unit adapted to contain charges tobe heated, a

pair of electrodes, a second pair of electrodes, means for conveyingsaid unit between such pairs of electrodes, means for causing the firstpair of electrodes to engage the charges in said unit to preheat themmeans for causing the second pair of electrodes to heat said chargesafter they have been preheated.

11. In an electric furnace, a plurality of independent units adapted tocharges to be heated, a pair ele )(iGS,

supporting means for moving said un cessively between the electrodes andmeans for removing the treated charges from the units.

12. In an electric furnace, a plurality of independent units adapted tocontain charges to be treated, a pair of electrodes, supporting meansfor moving said units successivelybetween the electrodes, means formoving the electrodes against the charges and means for removing thetreated charges from the units.

. 13. In an electric furnace, a plurality of independent units adaptedto contain c to be treated, supporting means for said.

units, a pair of electrodes, a second pair of electrodes, means forcausing the of electrodes to engage the charge to preheat it and meansfor causing the second pairto engage the charge to complete the heating14. In electric furnaces, a furnace unit containing a charge to beheated, a revolublemoved toward or away from said unit.

15. In electric furnacesa revoluble frame, a plurality of furnace unitssecured to said frame, heating electrodes spaced apart, means for movingthe electrodes toward or from tne units and a stop to hold the saidframe with a furnace unit in position between the electrodes.

16. In electric furnaces, a revoluble frame, a plurality of furnaceunits pivoted to said frame, and a trip projecting into the path of theunits to cause them to discharge their contents when moved adjacentthereto.

17. in electric furnaces, a revoluble frame, a plurality of furnaceunits pivoted thereto, a pair of electrodes spaced apart, means formoving the electrodes toward or from said units, a trip projecting intothe path of the said units adapted to cause them to revolve on theirpivots to discharge their contents and a bin to receive said contents.

18. In electric furnaces, a plurality of furnace units containingcharges to be heated, a pair of electrodes spaced apart, a source of E.M. F. applied to said electrodes, :1 second pair of electrodes spacedapart, a

source of E. M. F. applied to said second,

pair of electrodes, said second source having greater voltage than thefirst source, and means for moving said furnace units between the firstpair of electrodes to be preliminarily heated, and ,then between thesecond pair of electrodes to be completely heated.

19. In an electric furnace installation, the combination of a pluralityof furnaces ar ranged side by side, electrodes therefor at the operatingposition of the furnace, and means whereby a part of each of thefurnaces may be moved from the operating position and electrodestoreceive and discharge material.

In testimony whereof I have hereunto signed my name.

JOHN W. BROWN.

lVitnesse's RALPH H. ATKINSON, GEORGE H. BROWN.

fiepies of this patent ma be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington. D. C.

